Field of the Disclosure
The disclosure relates to radio resource management and more particularly relates to a transceiving apparatus and a spectrum access controlling method thereof.
Description of Related Art
The rapidly growing demand and throughput of mobile networks (e.g., the third generation (3G) and fourth generation (4G) mobile communications) have prompted telecom operators to seek more spectrum or build more base stations. Regarding the available spectrum, referring to FIG. 1, in addition to obtaining licensed spectrum through the official authorities, telecom operators may utilize an unlicensed spectrum to provide data offload or carrier aggregation (CA) for transmission on the licensed spectrum. Although there may be many signals of other communication technologies (e.g., Wi-Fi, Bluetooth, and so on) in the unlicensed spectrum, the standards related to mobile networks have provided a Listen Before Talk (LBT) mechanism to effectively avoid a collision. For example, on the basis of LTE Licensed Assisted Access (LAA)/Enhanced Licensed Assisted Access (eLAA) technologies in the Third Generation Partnership Project (3GPP) Long Term Evolution-Advanced (LTE-A) pro R13/R14 standards, the user equipment (UE) and the base station (BS) will perform carrier energy detection on the unlicensed spectrum before accessing the unlicensed spectrum, so as to prevent a collision with the signals transmitted by other devices on the unlicensed spectrum. If the signal strength measured on the unlicensed spectrum is greater than an energy detection threshold, the UE and the BS determine that this unlicensed spectrum is in a busy state and wait. On the other hand, if the signal strength detected on the unlicensed spectrum is not greater than the energy detection threshold, the UE and the BS determine that this unlicensed spectrum is in an idle state, and the UE and the BS will use this unlicensed spectrum for uplink/downlink data transmissions. The above-described mechanism is the clear channel assessment (CCA) procedure.
It is known from the above that the energy detection threshold is an important factor for assessing whether the UE and BS can access the unlicensed spectrum for data transmissions. According to the current technology, however, the UE and BS use only one preset energy detection threshold for evaluating the accessibility of the unlicensed spectrum. As the use or quality of the unlicensed spectrum changes, using one single preset energy detection threshold may result in a long idle time for the spectrum or a data transmission collision. Therefore, the current mechanism for accessing the unlicensed spectrum needs to be improved.